Chapter 6.3, Problem 3.1CYU

To determine

To find: The mean of X.

Answer to Problem 3.1CYU

The mean of X is 2.

Explanation of Solution

Given:

Number of questions = 10

Students are supposed to guess the answers.

X is a number of answers that Patti gives correct.

Probability of success ( p ) = 0.2

Formula used:

The formula to compute the mean using binomial distribution is:

  $\mu =n\times p$

Calculation:

The mean of X is computed as:

  $\begin{array}{c}{\mu }_X=n\times p\\ =10\times 0.2\\ =2\end{array}$

Thus, the mean of X is 2.

Interpretation:

The mean of X shows that it could be expected that out of 10 questions, 2 questions will be guess correctly by Patti.